Research progress in high-temperature failure behavior of MCrAlY metal bond-coat

Abstract

The MCrAlY(M=Ni, Co or NiCo)has become a widely used bond-coat material of thermal barrier coatings (TBCs) due to its advantages of high-temperature oxidation resistance and high thermal expansion coefficient, with the continuous increase in turbine inlet temperature of aero engines and gas turbines. However, the stress distribution at the interface between the bond and top coating in thermal barrier coatings becomes more complicated under a high-temperature service environment. The failure of the bond-coat leads to the spalling of the top coating, which limits the development of the thermal protection coating field. The development process of the bond-coat was briefly described.The failure behavior of the bond-coat interface due to high-temperature phase transition, increased thermal and growth stresses, and S-element diffusion was focused on, and the failure mechanism of the bond-coat interface was analyzed. The research on improving the bond-coat interface failure at home and abroad was summarized. The synergistic strengthening of MCrAlY by rare earth and nanoparticles is proposed, which provides a research direction for the future optimization design of thermal bond-coat systems.

Keywords

• metal bond-coat
• mcraly
• failure mechanism
• modified research